This disclosure relates to oligomeric compositions useful in the preparation of polymeric compositions. In particular, this disclosure relates to oligomeric polyol compositions useful in the preparation of polyurethane compositions.
Polyurethanes are important industrial polymers used in a wide variety of applications including rigid and flexible foams, thermoplastic and thermosetting elastomers, sealants, coatings and adhesives, elastomeric fibers, and synthetic leather-like materials. Most polyurethanes used commercially are elastomers with Young's moduli less than about 50,000 psi, but some polyurethanes in unfilled form have moduli ranging from 250,000 psi to 500,000 psi or more. Examples include TPU engineering plastics (Isoplast®) and a number of commercial cast systems. Polyurethanes have several shortcomings including the need for mold release agents, long demold times (poor green strength) and intense in-mold exotherms that can cause visual imperfections in the final part. Such imperfections include color change and surface splay from outgassing. Most polyurethane elastomers are generally not used for structural applications due to their typical low modulus and strength. The flexural moduli of most polyurethane compositions are well below 300,000 psi and flexural strength values are typically below 10,000 psi. Known polyurethanes may be deficient in terms of their resistance to heat, and are frequently characterized by heat distortion temperatures which are less than 100 degrees centigrade. In addition, upon exposure to conditions of high humidity at moderate temperature known polyurethanes may exhibit significant loss of material properties.
U.S. Pat. No. 8,110,710 discloses the reaction of bisphenol A polycarbonate with aliphatic diols to produce a mixture of bisphenol A hydroxy alkylene ethers and free bisphenol A. The reference does not disclose the formation of oligomeric polyols comprising an oligomeric network comprising residues of at least one polyhydroxylated aromatic compound and residues of at least one polyol having at least three hydroxyl groups.
Non-patent reference Process Safety and Environmental Protection, Volume 100, Pages 281-287, 2016 discloses the reaction of bisphenol A polycarbonate with glycerol to produce a mixture of free bisphenol A and the mono and diglycerol ethers of bisphenol A. The reference does not disclose the formation of oligomeric polyols comprising an oligomeric network comprising residues of at least one polyhydroxylated aromatic compound and residues of at least one polyol having at least three hydroxyl groups.
International Application WO 2015/132080 A1 discloses the reaction of 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate with an oligomer of the mono-glycidyl ether of bisphenol A to provide an adduct comprising two terminal residues of 2-hydroxyethyl 2-oxo-1,3-dioxolane-4-carboxylate which is subsequently reacted with a diamine to produce a linear polyurethane. The reference does not disclose the formation of oligomeric polyols comprising an oligomeric network comprising residues of at least one polyhydroxylated aromatic compound and residues of at least one polyol having at least three hydroxyl groups. Nor does the reference disclose a polyurethane prepared from such an oligomeric polyol and advantages attendant the incorporation of such oligomeric polyols into highly crosslinked polyurethanes.
Thus, there is a need for new polyurethane compositions which exhibit superior heat resistance, enhanced stability in the presence of water, improved strength, hardness, and molding characteristics relative to known polyurethane materials. There is a need for starting materials useful in preparing polyurethane based compositions which exhibit superior heat resistance, enhanced stability in the presence of water, improved strength, hardness, and molding characteristics relative to known polyurethane materials.